The present invention relates to a radiation irradiation method and a radioactive beam irradiation apparatus.
In Japanese Patent Application Laid-Open No. 59-88160 (1984), there is disclosed a radiation irradiation control apparatus for controlling a target area of beam irradiation by detecting a three-dimensional position of a diseased part using an ultrasonic tomography apparatus.
In general, in radiation therapy using proton and heavy particles, the resolution of the target position of the irradiation is higher, and thus, there is an advantage that a proper dose of irradiation to the diseased part can be obtained. However, in case the position of the diseased part is subject to physical activity, such as movement due to breathing and heart beat, the dose to be irradiated to the diseased position is reduced and hence, the expected effect for the therapy can not be attained. The physical movement and similar phenomena, such as movement caused by breathing and heart beat, is designated "physical activity". In the prior art, since real-time control of the irradiation direction and position is necessary, with the diseased position measurement being carried out in real-time as well, a complex apparatus is necessary for measuring the position of the diseased part and for controlling the radiation therapy apparatus.